Radio tuning indicator



June 28, 1938. w. J. SCHNELL 2,122,323

RADIO TUNING INDICATOR Filed May 15, 195"! 2 Sheets-Sheet 1 Mum/J had@211 7710020 @5:

June 28, 1938. w, J SCHNELL 2,122,328

RADIO TUNING INDICATQR Filed May 15, 1937 2 Sheets-Sheet 2 Patented June28, 1938 UNITED STATES aamo TUNING mnrca'roa William J.

trical Research Laboratories Inc., Chicago,

Schneli, Berwyn, Ill., assignor to Eleca corporation of IllinoisApplication May 15, 1937, Serial No. 142,864

8 Claims.

This application relates to a tuning indicator for radio receivers andthe like.

In present day receivers of the most expensive type, so-called automatictuning aids operable by various devices, such as telephone dials, pushbuttons and the like, have been provided for the purpose of facilitatingtuning of the receiver in accordance with the call letters of a numberof the most usually selected broadcasting stations.

It is an object of applicants invention to provide a tuning indicatorfor the small and inexpensive class of radio receivers, which tuningin-' dicators shall be simple in construction, inexpensive in cost, andeflicient in operation.

A further object of applicant's invention is to provide an inexpensiveand eflicient marking device indicating the position to which the tuningelement of the receiver should be moved to tune the receiver to thestation represented by call letters inscribed on the marking device.

It is another object of applicant's invention to provide a plurality oftabs adapted to be inscribed with the call letters of any selectedcombination of broadcasting stations and inexpensive but eiiicient meansto detachably mount said tabs upon the dial of a radio receiver.

A further object of the invention is to provide simplified inexpensivemeans operable in synchronism with the tuning element of the receiver togive a selective indication of the station to which the receiver istuned.

Another object of the invention is to provide, in a radio receiver, aplurality of marking devices and means selectively illuminating themarking device representing the station to which the receiver is tunedat any instant.

Numerous other objects and advantages will be apparent from aconsideration of the following specification when taken in considerationwith the drawings disclosing one form of a device constructed inaccordance with the principles of the present invention and in which-Fig. 1 represents a perspective view of a radio embodying applicant'sinvention;

Fig. 2 and Fig. 3 are exploded views in perspective showing the variousparts of the mechanism;

Fig.4isaviewofa plicants invention;

Fig. is a vertical section taken along the line 5-5 of Fig. 6, and

Fig. 6 is a vertical section taken along the line B-5 of Fig. 1.

As shown in Fig. 1, a radio cabinet I is providmarking tab used in apedwith a dial assembly 2 visible through an opening in the front face ofthe cabinet, which opening, in the usual manner, is bounded by adecorative escutcheon 3. The dial assembly 2 comprises a frame orsupporting plate 4- bolted or 5 otherwise secured to the front panel ofthe radio cabinet. The frame 6 is generally rectangular in configurationand is provided with a rectangular opening 5. At the bottom of theopening a pair of brackets 6, secured to the front face of the 10 frameprovide a shelf on which is supported a sheet I and a' glass plate 8.The sheet I is generaily rectangular in shape; is somewhat larger thanthe opening 5 and is provided with a preferably circular opening 9. Thefront surface of the sheet I is blackened to prevent the reflection ofrays toward the glass plate 8. This plate 8 is of a size substantiallyequal to the sheet I and on its front face are etched one or moresemi-circular scales l0 marked with indicia representative of one ormore broadcast bands. The back sheet 1 and the glass plate 8 are securedto the frame land held against outward movement by a plurality of clampsH. The clamps H are secured to the rear of the frame 4, passing throughrecesses I2 in the frame, and have portions l3 overlying the. corners ofthe glass plate 8.

A lamp It is mounted by a bracket 15 on the upper edge of the frame 4and a shield i6, surrounding the lamp M, is provided with a longitudinalslot I! in alignment with the glass plate 8. The lamp It serves as ameans for diffusely illuminating the scales ill by edge-lighting theglass plate 8.

A tuning condenser iii of any ordinary form is mounted in the usualmanner on the radio receiver chassis I9 and on the shaft 20 of thetuning condenser there is mounted, by a collar 2|,

a set screw 22 and a washer 23, a disc 24. The disc 24 is made of anysuitable transparent or translucent material such as Pyroxylin and iscoated on its rear surface with an opaque material, preferably black, insuch a manner as to leave radially aligned transparent strips or lines25 in the coating. The disc 24 is operated by a pair of fiber discs 26carried on the inner end of a shaft 21 which is operable by a knob 28. Alamp 29 is mounted by a bracket 30 on the' collar 2| in alignment withthe transparent strips 25.

It will be apparent that'for the coated disc 24 there may be substituteda like disc of opaque material having radially aligned slots allowingpassage of the light therethrough.

A metallic plate 3| is secured to the frame I to provide resilientsections 34 under which a marking tab 35 is adapted to be inserted andfrictlonally held against the glass plate 8. The resilient sections 34are bent forwardly at their outer ends, as at 36, to facilitate theinsertion of the tabs 35. The tabs 35 comprise transparent strips uponwhich there is or is adapted to be inscribed the call letters of desiredbroadcasting stations.

The frame 4 and associated parts are mounted on the chassis is by abracket 31 fastened to the rear surface of the frame 4 and secured tothe condenser housing as by bolts 38. The bracket 31 is provided with asubstantially semicircular opening 39 forming a bearing for the shaft 20of the condenser.

In use, tabs 35 are prepared by inscribing the same with the callletters of the most frequently selected broadcasting stations; thereceiver is tuned in turn to these stations and the tabs are in turninserted under the lips 36, being pressed between the resilient sections34 of the plate 8| and the glass plate 8 in alignment with theilluminated transparent slits or strips 25.

It will be seen that applicant has provided a radio receiver having aplurality of marking devices, and has provided means for selectivelyilluminating the marking device representing the station to which at anyinstant the receiver is tuned.

Changes may be made in the form, construction and arrangement of theparts without departing from the spirit of the invention or sacrificingany of its advantages, and the right is hereby reserved to make all suchchanges as fairly fall within the scope of the following claims.

The invention is hereby claimed as follows:

1. In apparatus of the character described, the combination of dialmeans comprising a lighttransmitting plate and a scale visible throughsaid plate, a second plate in clamping engagement with said first plateand having an opening through which said scale may be viewed, and aplurality of marking tabs adapted to be inscribed with indiciarepresentative of selected broadcasting stations, said second platehaving a plurality of resilient sections for frictlonally clamping saidtabs between said first and second plates.

2. In apparatus of the character described, the combination of dialmeans comprising a light transmitting plate and a scale visible throughsaid plate, a second plate in clamping engagement with said first plateand having a semicircular opening concentric to said scale, a pluralityof marking tabs each adapted to be inscribed with indicia representativeof a selected broadcasting station, said second plate being radiallyslit at equally spaced points to form a plurality of resilient sectionsfor frictlonally clamping said tabs between said first and secondplates.

3. In apparatus of the character described, the combination of atranslucent plate, an arcuate scale marked on one surface of said plate,means for directing rays of light against said plate diflusely toilluminate said scale. a second plate in clamping engagement with saidfirst plate and having an opening concentric to said scale, and aplurality of marking tabs each adapted to be inscribed withindiciarepresentative of a selected broadcasting station, said secondplate directing rays of light against said plate diffusely to illuminatesaid scale, a second plate and scale in clamping engagement with saidfirst plate and having an opening concentric to said scale, and aplurality of marking tabs adapted to be inscribed with indiciarepresentative of a selected broadcasting station, said second platehaving a plurality of resilient sections for frictlonally clamping saidtabs between said first and second plates, a tuning element, a drivingshaft for operating said element, luminous means carried by said shaft,a shutter carried by said shaft and interposed between said plate andsaid luminous means for directing a concentrated beam of light from saidluminous means upon said plate selectively to illuminate various ones ofsaid tabs in accordance with the position of said tuning 'element.

5. In apparatus of the character described, the combination of atranslucent plate, an arcuate scale marked on one surface of said plate,means for directing rays of light against said plate diffusely toilluminate said scale, a second plate in clamping engagement with saidfirst plate and having an opening concentric to said scale, and

a plurality of marking tabs adapted to be inscribed with indiciarepresentative of a selected broadcasting station, said second platehaving a plurality of resilient sections for frictlonally clamping saidtabs between said first and second plates, a tuning element, a drivingshaft for operating said element, luminous means carried by said shaft,a transparent disc having an opaque coating with an opening in saidcoating forming a transparent strip in alignment with said luminousmeans, said disc being carrled by said shaft and interposed between saidplate and said luminous means for directing a concentrated beam of lightfrom said luminous means upon said plate selectively to illuminatevarious lines of said scale and various ones of said tabs in accordancewith the position of said tuning element.

6. In apparatus of the character described, the combination of atranslucent plate, an arcuate scale marked on one surface of said plate,means for directing rays of light against the edge of said platediffusely to illuminate said scale, a second plate in clampingengagement with said first plate and having an opening concentric tosaid scale, and a plurality of marking tabs adapted to be inscribed withindicia representative of a selected broadcasting station, said secondplate having a plurality of resilient sections for frictlonally clampingsaid tabs between said first and second plates, a tuning element, adriving shaft for operating said element, luminous means carried by saidshaft, a disc having a narrow radial slot in alignment with saidluminous means, said disc being carried by said shaft and interposed fortriotlondlly clamping said tabs between said 10 plate and the dial coverplate.

8. Means for detachebly securing a. plurality oi marking tabs to thedial cover plate of s mdio receiver, comprising a. plate adapted to bepieced in clamping engagement with the cover plate, said plate beingradially slit at equally spseed points to form a. plurality of resilientsections for friotionelly clamping the marking tabs between seid plateand the dial cover plate.

